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"On my part, I remain committed to the process of dialogue. It is my firm belief that dialogue and a willingness to look with honesty and clarity at the reality of Tibet can lead us to a viable solution."

Report: The Snooping Dragon: social-malware surveillance of the Tibetan movement

March 30, 2009

Shishir Nagaraja, Ross Anderson
Technical Report Number 746
Computer Laboratory, University of Cambridge
March 2009

UCAM-CL-TR-746
ISSN 1476-2986
15 JJ Thomson Avenue
Cambridge CB3 0FD
United Kingdom
phone +44 1223 763500
http://www.cl.cam.ac.uk/

©2009 Shishir Nagaraja, Ross Anderson
This material is based in part upon work
supported by the U.S. Department of Homeland
Security under Grant Award Number
2006-CS-001-000001, under the auspices of the
Institute for Information Infrastructure
Protection (I3P) research program. The I3P is
managed by Dartmouth College. The views and
conclusions contained in this document are those
of the authors and should not be interpreted as
necessarily representing the official policies,
either expressed or implied, of the U.S.
Department of Homeland Security, the I3P, or
Dartmouth College. Technical reports published by
the University of Cambridge Computer Laboratory
are freely available via the Internet: http://www.cl.cam.ac.uk/techreports/
ISSN 1476-2986

Information Trust Institute
University of Illinois at Urbana-Champaign
sn275@iti.uiuc.edu
Ross Anderson
Cambridge University
Computer Laboratory
Ross.Anderson@cl.cam.ac.uk

Abstract

In this note we document a case of malware-based
electronic surveillance of a political
organisation by the agents of a nation state.
While malware attacks are not new, two aspects of
this case make it worth serious study. First, it
was a targeted surveillance attack designed to
collect actionable intelligence for use by the
police and security services of a repressive
state, with potentially fatal consequences for
those exposed. Second, the modus operandi
combined social phishing with high-grade malware.
This combination of well-written malware with
well-designed email lures, which we call social
malware, is devastatingly effective. Few
organisations outside the defence and
intelligence sector could withstand such an
attack, and although this particular case
involved the agents of a major power, the attack
could in fact have been mounted by a capable
motivated individual. This report is therefore of
importance not just to companies who may attract
the attention of government agencies, but to all
organisations. As social-malware attacks spread,
they are bound to target people such as
accounts-payable and payroll staff who use
computers to make payments. Prevention will be
hard. The traditional defence against social
malware in government agencies involves expensive
and intrusive measures that range from mandatory
access controls to tiresome operational security procedures.

These will not be sustainable in the economy as a
whole. Evolving practical low-cost defences
against social-malware attacks will be a real challenge.


1 Introduction

Following the Chinese invasion of Tibet, the
Dalai Lama fled in 1959 to exile in India from
where he has acted as the Tibetan spiritual
leader and campaigned for Tibetan independence.
His campaign has often embarrassed the Chinese
government. In the runup to the Peking Olympics
of 2008, Tibet was particularly sensitive; bloody
anti-Chinese riots in Lhasa and elsewhere in
March 2008 were followed by a police crackdown
involving many arrests and killings. The crackdown continues to this day.

The activities of the Dalai Lama and the Tibetan
government in exile are coordinated by the Office
of His Holiness the Dalai Lama (OHHDL) in
Dharamsala. Most of its activities are quite
overt and have to do with the Dalai Lama's
diplomatic and campaigning work, including
overseas trips, and his spiritual mission which
ranges from religious festivals through pastoral
care for Tibetan refugees to routine scholarly
work. Some of this work has of necessity a covert
element. For example, a campaigning group such as
the OHHDL may plan a publicity coup in secret for
maximum effect. A tactical matter like this may
require secrecy only for a few weeks or months,
and the consequences of a leak are typically mild
{ loss of operational effectiveness. However
there are other covert matters where secrecy must
be maintained for much longer, and the
consequences of a leak may be severe. An example
comes from schooling. While organising
Tibetan-language schools in India or the USA is
an open matter, such schools in Tibet itself may
have to be covert. Their operation may place
teachers' and even students' lives at risk.
Indeed, everyone associated with the Tibetan
movement who sets foot in Tibet or China is at
risk of their lives. Another potentially
sensitive information asset is a database of
Tibetan refugees, including where they lived in
Tibet, when they left and where they live now.

The OHHDL first started using the Internet to
publish talks and speeches in the 1990s [1].
Since then, the use of IT in its daily activities
has grown steadily. Email is now the staple means
of communication within both the OHHDL and other
arms of the Tibetan movement. Tibetans also
generate a growing number of electronic documents
in the process of scholarship and administration.
Most of this is routine, but some documents are
sensitive in the strong sense that they could be
used to construct actionable intelligence for
Chinese government agencies leading to fatal
consequences for people in Tibet and China. In
what follows, we will follow NATO practice and
call such documents `secret', while documents
whose compromise will merely cause a loss of
operational effectiveness (such as those relating
to forthcoming political meetings) we will call
`confidential'. (In the past, the Tibetans did
not differentiate between levels of sensitivity.
Secret documents were sometimes sent by email;
confdential documents still are.) As in other
organisations, the ease of communication brought
by the Internet has shifted the social rules for
information management. Many of the safeguards
available in the world of paper les are much
more dicult to implement in the electronic world
in ways thet provide both adequate strength of
mechanism and acceptable usability. This raises
the diffcult and (now) urgent problem of what
combination of technical controls and procedural
measures are needed in the new world of online working.

2 Attacks on the Dalai Lama's Private Office

The OHHDL started to suspect it was under
surveillance while setting up meetings between
His Holiness and foreign dignitaries. They sent
an email invitation on behalf of His Holiness to
a foreign diplomat, but before they could follow
it up with a courtesy telephone call, the
diplomat's office was contacted by the Chinese
government and warned not to go ahead with the
meeting. The Tibetans wondered whether a computer
compromise might be the explanation; they called
ONI Asia who called us. (Until May 2008, the
first author was employed on a studentship funded
by the OpenNet Initiative and the second author
was a principal inviestigator for ONI.)

Email users at the OHHDL have been suffering spam
attacks for some time. While some of these are a
part of a wider pattern of attacks on anyone
plausibly associated with the Tibetan movement,
others are specifically targeted at OHHDL users.
The web-hosting and email services used by the
OHHDL are provided by a California company. A
look at the email server logs revealed a number
of successful logins from a range of IP addresses
that belonged to Chinese and Hongkong ISPs, with
which none of the OHHDL email users were
associated. Given that there are fewer than 50
email accounts, the possibiliy of error or
accident seemed low { and especially so as many
of the suspicious source IP addresses belonged
(according to APNIC) to ISPs operating not just
in the Chinese mainland, but in China's Xinjiang
Uyghur Autonomous Region, where police and
intelligence units dealing with Tibetan
independence campaigners are based. Folowing
discussions with the OHHDL, the first author
travelled to Dharamsala in September 2008 to
assist in a forensic investigation. A technical
report on the background to this investigation,
and on follow-up visits to Tibetan offices round
the world by ONI Asia personnel, is published
separately by ONI Asia and CitizenLab [2]. The
purpose of this paper is to set out the technical
findings of our investigation and discuss their wider implications.

We monitored the network traffic from the OHHDL
to its mail service in California and immediately
observed that gaining access to emails would have
been straightforward for anyone who could monitor
this circuit, since the traffic was unencrypted.
The email server could be contacted via POP, IMAP
and HTTP in insecure modes, with passwords and
mail passing in plain text. We also noted that
some passwords chosen by monks were easily broken
with a dictionary attack using John the Ripper in
about 15 minutes [3]. The `standard'
security-consultant advice might therefore have
been that the monks turn on TLS encryption to
their mail server, and adopt a password policy.
However such a superficial diagnosis and
prescription would not have given the Tibetans
much of a defence. It turned out that the attackers used a diffierent route.

2.1 The attack vector

Email attachments appear to have been the
favoured strategy to deliver malicious payloads.
This worked because the attackers took the
trouble to write emails that appeared to come
from fellow Tibetans and indeed from co-workers.
The use of carefully-written email lures based on
social context to get people to visit bogus
websites has been called `social phishing' [4];
in this incident, such email was used to spread
malware and we therefore call this strategy social malware.

Figure 1: One of the tampered emails used to spread malware

The initial break may have been facilitated by
the fact that the monks in the OHHDL were not
just engaged in administrative tasks but were
also active on various discussion sites. A
passive observer could easily note their names,
their interests and the names of people with whom
they interacted. Emails were sent to monks,
purporting to come from other monks, but that had
in fact come from outside. We assume that one
monk clicked on an infected attachment, giving
the attackers their first foothold. It is
possible that the initial break came from
somewhere else, such as a guessed password for
the mail server, or a mail server compromise; but
we did not see evidence of the pattern of
compromise likely after a passive wiretap, or of
malware attacks on the mail servers themselves.
We assess that the attackers probably used
publicly-accessible mailing-list archives to
construct the social-malware emails that they sent to their first targets.

Our analysis strongly suggested that once they
has secured an initial foothold, the attackers
gained access to the mailboxes of several users
at the mail server. The successful logon attempts
from China recorded from the mail server log
point to this. They then used social engineering
based on the contents of internal emails to
expand this compromise to infect many other
machines at the OHHDL. In particular, they
targeted the email addresses of prominent members
of the OHHDL and of key support staff including the system administration team.

An interesting and very effective twist was that
the attackers did not just use the social
information they gained from their initial attack
to send plausible phish. They also stole mail in
transit and replaced the attachments with toxic
ones. Figure 1 shows an email whose body was
stolen from the mailbox of a user and then used
to construct the attack by attaching a malicious payload.

2.2 The payload

Our next observation concerns the malware
payloads used. These were packaged as either .doc
or .pdf files that installed rootkits on the
machines of monks who clicked on them. During our
initial network monitoring exercise, we observed
sensitive files being transferred out of the
OHHDL using a modified HTTP protocol: the malware
picked up files from local disks and sent them to
three servers which, according to APNIC, were in
China's Sichuan province, using a custom protocol
based on HTTP. The malware uses HTTP GET and HTTP
POST messages to transfer files out and also
appears to verify successful transmission.
Sichuan, by the way, is the location of the
Chinese intelligence unit specifically tasked with monitoring the OHHDL.

We then examined samples of email attachments
from the local filesystems them with the expert
help of Mikko Hypponen at F-Secure Corporation,
who determined that they could support file
search and retrieval operations and also function
as keyloggers. This confirms that the attackers
had pretty much full access to the data on the
infected computers. (In fact, one monk claimed
that he actually `saw' the bot open his Outlook
Express and send infected attachments to others
without any action on his part!)

2.3 The attackers' operational security

We initially expected that the attackers would
seek some form of anonymity, perhaps by attacking
through intermediate relays, or maybe an
anonymity service such as Tor [5] -- the largest
such system. But a comparison of the IP addresses
used in the attack with Tor exit node IP
addresses (both in China and elsewhere) proved
negative. However, after a while, we saw a number
of accesses through Dynaweb -- a set of
anonymisation proxy servers associated with the
Falun Gong religious movement, which is also
detested by the Government of China. We are at a
loss how to explain this. Perhaps the Chinese
detected the start of our clean-up operation and
decided to hint that they had compromised Dynaweb
{ whether to deter people from using it, or to
deter the US government from funding it? We just have no idea.

With hindsight, the Tibetans were fortunate in
that the Chinese made the operational error of
using surveillance product for a minor and
tactical diplomatic purpose. By demonstrating
that they had access to confidential data, they
alerted the OHHDL to worry about the secret data
too. This underlines the wisdom of the
traditional NATO doctrine of treating
communications intelligence product as Top Secret
Codeword and enforcing very severe restrictions on its use.

3 Analysis and Countermeasures

The informal security model used at the OHHDL (as
in most companies) was essentially one of
discretionary access control: users were trusted
to use computer resources sensibly. Yet we
observed users storing secret documents on the
local filesystem of a computer also used for
risky activities such as browsing the Internet
and opening emails with attachments from
colleagues (actually strangers pretending to be
colleagues). The handling of sensitive data was
thus inadequately separated from risky activities
-- activities that require the user to trust content from strangers.

Next, although the attacks we document here came
from the intelligence services of a major
country, there is nothing in the modus operandi
that prevents them from being carried out by a
smaller opponent. For example, we saw no evidence
that the initial break involved wiretapping the
backbone traffic from Dharamsala to California --
the kind of exploit popularly associated with a
large-country agency. There was no need, given
the tools and methods they actually employed. In
fact, even a capable motivated individual could
have carried out the attacks we describe here.
Until recently, one might have assumed that it
would take a `geek' to write good malware, and
someone with interpersonal skills to do the
social manipulation. But the industrialisation of
online crime over the past five years means that
capably-written malware, which will not be
detected by anti-virus programs, is now available
on the market. All an attacker needs is the
social skill and patience to work the malware
from one person to another until enough machines
have been compromised to complete the mission.
What's more, the `best practice' advice that one
sees in the corporate sector comes nowhere even
close to preventing such an attack.

Thus social malware is unlikely to remain a tool
of governments. Certainly organisations of
interest to governments should take proper
precautions now, but other firms had better start
to think about what it will mean for them when
social malware attacks become widespread. What
Chinese spooks did in 2008, Russian crooks will
do in 2010, and even low-budget criminals from
less developed countries will follow in due
course. So what are the broader implications? How
can social malware be dealt with?

3.1 Countermeasures for NGOs

The first question is what defences are available
to an organisation such as the OHHDL. The world
of defence computing gives us a workable, if very
expensive, answer. It starts with the use of
mandatory access controls (MAC) to provide strong
separation of processes and data. At its
simplest, the Bell-LaPadula model ensures that
information may flow up from Low to High but not
down; this is also known as multi-level security
(MLS). An immense research programme, lasting
over thirty years, led to the creation of
software products and an assurance infrastructure
to support this model; a good introduction may be
found in [7]. Until recently, high-grade MAC/MLS
products were not available to normal users and
were even export-controlled; but now products
such as Trusted Solaris and SELinux are available
without restriction. But could a typical
organisation use these tools e ectively?

The classical MAC/MLS approach to the Tibetans'
protection problem would start with a system of
information classification, as we discussed
already. A firewall or mail guard implemented on
an SELinux platform might be used to ensure that
no secret documents are made available to
resources at a lower level, such as a machine on
which external email or web pages had been read.
And clearances matter as well as
classiffications. Access to secret documents
would be restricted to staff who have at the very
least had a background check -- otherwise Chinese
agents can simply walk over the border from Tibet
and volunteer to work at the OHHDL.

Then there's the hardest part -- operational
security. How do you train your staff so that
they won't fall prey to social engineering
attacks? An old NSA security manual that fell
into the public domain in the early 1990s gives
some insight of the lengths that the agencies go
to to prevent hostile agencies targeting their
staff [8]. The emphasis is not just on discretion
but on anonymity. This again is sound advice for
any organisation that handles real secrets { only
a handful of carefully-chosen people should have
access to the secrets, their names should not be
public, and they should have a low profile online.

However, it is against the Dalai Lama's policy to
have any secret organisations.  Finally there's
the red team. It's important to test your
defences; we discovered the extent of the
compromise rapidly when we started monitoring the
traffic to and from the OHHDL. One technique is
to probe your operational security. Phone up your
own organisation and see what you can extract
with just a little bit of guile; Mitnick's book
has lots of ideas to work with [9]. But there are
limits on the level of operational security that
can be sustained outside the world of defence and
intelligence. Most companies would rather not
teach staff to be (even more) unhelpful to
customers and to each other, and few religions
would want to train their headquarters staff to
be rude to the faithful. Where there is a
dedicated cell of people handling secret data,
the regular operational security testing e ort
should be directed at them. The organisation as a
whole should place greater emphasis on monitoring
outgoing traffic to see whether anything is
escaping that shouldn't, such as the names (or
cover names) of staff involved in field work, and
of some of the people in the refugee database.

Overall, our fieldwork brought home to us that a
small organisation wit few secrets, such as the
OHHDL, is likely to fund the engineering costs
and administrative overhead of doing multilevel
security to NSA standards to be unsustainable. It
is much more practical to keep the secret data on
machines in a separate building with no network
connection { or better still, to work with pen
and paper. The access conrtol, opsec and network
monitoring can become much more manageable if
secret data are kept away from network-attached computers.

3.2 Countermeasures for companies

What happens when criminals start using social
malware to attack companies? No-one should think
that it could not happen to them, just because
their company is in New York or London rather
than an Indian hill station! The Tibetan
sysadmins were just as capable as one finds in
the USA or Britain. Indeed, they were probably
more aware of the Chinese threat and as a result
more alert than a typical company security team.
They observed that a security compromise might
have taken place, and called expert help.
Furthermore, they have permitted us to document
what happened. All in all, the Tibetans'
performance has been more effective than we would
have expected from a randomly-chosen Western organisation.

There have been reports before of Chinese
industrial espionage against defence companies in
the West, notably the 2008 annual report of the
U.S.-China Economic and Security Review
Commission, according to which U.S. government
agencies and defence companies have had their
unclassified networks compromised by Chinese
hackers [11]. But the evidence they heard on
these attacks was classified, and their report
lacks the technical detail that we provide here.
A fuller (if still non-technical) story is told
by U.S. military expert Timothy Thomas, whose
book tracks the history of Chinese information
warfare doctrine [10]. According to Thomas,
Chinese strategic thinkers consider that a state
of information warfare already exists between
them and the West; in an extension of the Cold
War, the West is already attacking China by
exporting subversive ideas to it over the
Internet. Both the attack on the Tibetans
described here, and the industrialespionage
attacks described elsewhere, are consistent with
the picture Thomas paints. In view of continuing
concerns about industrial espionage, strict
separation is indeed practiced in some sectors.
We are aware of one company that maintains
totally separate  networks for design work and
external communications; the typical lab has PCs
that connect to the CAD/CAM system, and PCs of a
different colour that connect to the Internet.
Draconian physical and procedural controls try to
prevent data leakage from one network to the
other. But while such arrangements may be
sustainable in a cost-plus defence-contracting
environment, they are too expensive for the
normal economy. So what will happen when normal
criminals start using social malware to steal money from normal companies?

A typical medium-sized company, or an operating
division of a large company, might pay several
thousand employees and tens of thousands of
invoices every month. So payments must be
automated. Typically this involves an accounting
package feeding a payment application supplied by
the company's bank. A crook could target the
payment PC directly, or proceed indirectly by
taking over the PC of an accounts payable clerk
or payroll clerk in order to input false data to the accounting system.

It is possible to make payment systems
malware-proof. Twenty years ago, the second
author worked at a bank that used a
cash-management system consisting of an
application that was run on a PC XT from a
write-protected floppy disk that also contained a
copy of the operating system, supplied by the
bank. This was a good design; it turned the PC
into a payment appliance and excluded the
simultaneous use of any other software, including
malware. Unfortunately, it has been downhill all
the way since then! It would in our view be
prudent practice to run a high-value payment
system on a PC that does not contain a browser or
email client, or indeed any other software at
all. Perhaps within a few years banks will insist
on this, and design payment applications that
won't run otherwise. (Microsoft sells a
stripped-down version of Windows for use in ATMs;
perhaps their market is about to grow.) Perhaps a
few years later we will see the payment function
becoming a hardware appliance: a tamper-resistant
device supplied by the bank that does nothing
except display payments and signs them when the
approval button is pressed. Cryptographers have
mused about such systems for years; perhaps
social malware will at last provide their killer application.

Designers of accounting systems will also need to
make more pessimistic assumptions. At present
such systems are designed to deal with the
presence of a single dishonest insider, using
mechanisms for separation of duty and audit.
Their vendors may take the view that a single
infected PC is no worse than a dishonest member
of staff. But it is in the nature of social
malware that a successful attack is likely to
compromise many of the machines in an oce. The
implications will require careful study. Banks
have a hard enough time coping with the effects
of phishing, where the computers of less than 1%
of customers may be under hostile control at any
one time [12]; how can you run an accounting
system if half the machines are under hostile
control? Will it be possible, for example, to
aanchor internal controls on a hardened payment
PC? Or should companies insist that accounting
staff use separate PCs for accounting and for
email? Initial discussions with accounting staff
suggest that this would be very tiresome. Is
virtualisation the answer? Within a few years, we may have to nd out.

One thing we predict, though, is that the social
response to the threat of social malware will be
slow and ineffective. This is because of
elementary security economics [13]. Banks will
try to shift the blame to accounting system
providers, and vice versa. The accounting vendors
will advise customers to lock down user PCs,
without being too explicit about how. Companies
seeking redress will find themselves up against
standard terms and conditions whereby both banks
and vendors disclaim liability; in many markets
they are oligopolistic suppliers, so may be able
to defend these contract terms for some time. The
banking regulators have shown that they believe
whatever the banks tell them, that they are
uninterested in protecting bank customers, and in
any case they have no expertise in information
security. The initial attacks will affect only a
minority of firms, so the rest will prefer to
blame the attacks on the victims' negligence
rather than acknowledging that their own policies
need to change. Many companies will rely for
advice on their auditors, and big audit firms,
being ponderous and bureaucratic, give the same
advice year-in yearout until litigation or
regulation forces change. In short, we predict
that the criminals who adapt social malware to
fraud will enjoy many years of rich pickings.
Indeed, if either of us were inclined to crime, this would be what we'd go for.

4 Conclusions

In this note we described how agents of the
Chinese government compromised the computing
infrastructure of the Office of His Holiness the
Dalai Lama. They used social phishing to install
rootkits on a number of machines and then
downloaded sensitive data. People in Tibet may
have died as a result. The compromise was
detected and dealt with, but its implications are
sobering. It shows how dicult it is to defend
sensitive information against an opponent who
uses social engineering techniques to install
malware. We have described this social malware
attack here and considered its consequences.
Although the attack we describe in this case
study came from a major government, the
techniques their agents used are available even
to private individuals and are quite shockingly
elective. In fact, neither of the two authors is
confident that we could keep secrets on a
network-connected machine that we used for our
daily work in the face of determined interest
from a capable motivated opponent. The necessary
restrictions on online activity would not be
consistent with e ective academic work.

Organisations that maintain sensitive information
on network-attached computers and that may have
such opponents had better think long and hard.
The implications are serious already for people
and groups who may become the target of hostile
state surveillance. In the medium term we predict
that social malware will be used for fraud, and
the typical company has really no defence against
it. We expect that many crooks will get rich
before elective countermeasures are widely deployed.

Acknowledgements: The first author is supported
by a generous grant from the I3P Consortium. We
are also grateful to a number of colleagues, some
of whom wish to remain anonymous, and most of all
to the Oce of His Holiness the Dalai Lama for
permission to write this report so that others
may learn from their experience. Established
governments appear unwilling to discuss their
experience of such attacks; the Tibetan openness
is by comparison truly enlightened.

References

[1] http://www.tibet.com was already active when
http://www.archive.org opened spidered it in
1996; http://www.tibet.net has been active since 2001
[2] "Tracking Ghostnet: Investigating a Cyber
Espionage Network", in Information Warfare Monitor JR02-2009, Mar 29 2009
[3] http://www.openwall.com/john/
[4] "Social phishing", Tom Jagatic, Nathaniel
Johnson, Markus Jakobsson, Filippo Menczer, in
Communications of the ACM v 50 no 10 (Oct 2007) pp 94{100
[5] "Tor: anonymity online", at http://www.torproject.org/
[6] "Dynaweb", at http://www.dit-inc.us/dynaweb
[7] `Security Engineering { A Guide to Building
Dependable Distributed Systems', Ross Anderson, Wiley 2008
[8] `The NSA Security Manual, at
http://www.cl.cam.ac.uk/~rja14/Papers/nsaman.pdf
[9] `The Art of Deception: Controlling the Human
Element of Security', Kevin Mitnick, William
Simon and Steve Wozniak, Wiley 2002
[10] `Dragon Bytes: Chinese Information-War
Theory and Practice', Timothy L. Thomas, Foreign
Military Studies Office, Fort Leavenworth, Kansas, 2004
[11] `2008 REPORT TO CONGRESS of the U.S.-CHINA
ECONOMIC AND SECURITY REVIEW COMMISSION', 110th
Congress, Nov 2008, at
http://www.uscc.gov/annual_report/2008/annual_report_full_08.pdf
[12] \Closing the Phishing Hole { Fraud, Risk and
Nonbanks", Ross Anderson, at Nonbanks in the
Payment System, Santa Fe, NM, May 2007; available
from http://www.ross-anderson.com
[13] `Security Economics and the Internal
Market', Ross Anderson, Rainer Böhme, Richard
Clayton and Tyler Moore, ENISA, March 2008;
shortened version in Workshop on the Economics of
Information Security (WEIS 08); available from http://www.ross-anderson.com

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